I'm running into an issue where The Quantity Discounts is not calculating my taxes properly.

Basically I in my order total table I have a subtotal (class ot_subtotal) and a shipping (ot_shipping).

I have 2 seperate tax groups for these.

When I have a quantity discount, when It calculates the tax it is doing the following:

1) (subtotal - Quantity Discount) * product_tax_rate
2) (shipping - Quantity Discount) * shipping_tax_rate

As you can see this causes a problem as it is discounting the quantity discount twice for (only for the calculating of tax).

While this doesn't seem like much, each transaction I'm not charging approx $1 of tax that I have to pay to the government...


Anyways any help would be appreciated. I haven't yet went into the quantity discount code to look at things as I would rather not have to :)